Brodtkorb T, Kogler GF, Arndt A. The influence of metatarsal support height and longitudinal axis position on plantar foot loading. Clin Biomech (Bristol, Avon). 2008;23(5):640-7.
Rothman KJ. Computation of exact confidence intervals for the odds ratio. Int J Biomed Comput. 1975 Jan;6(1):33-9.
Rothman KJ. Computer analysis for case-control studies with individual matching. Int J Biomed Comput. 1974 Oct;5(4):241-7.